I just rcvd my NanoVNA V2Plus4.  I have read through the "official" manual and it appears to cover the basics well but I do have one question.  From what I gather, there is no data (measurements) storage on the VNA device itself, is that correct?  Only using vna-qt (or similar) can I save measured data, yes?

I want to measure the impedance of my antenna at the antenna feed point, which of course is outdoors and requires a ladder.  I was hoping to take the VNA device only out to the antenna and record the data across the amateur bands, bring the unit inside and connect to vna-qt to view and analyze the data.  However, it seems I must take the laptop with vna-qt with me to the antenna to record the measurements; is that correct?

Thank you es 73
Matt  W5MT

On 8/22/22 11:36 AM, Matt Thomas W5MT via groups.io wrote:
> I just rcvd my NanoVNA V2Plus4.  I have read through the "official"
> manual and it appears to cover the basics well but I do have one
> question.  From what I gather, there is no data (measurements) storage
> on the VNA device itself, is that correct?  Only using vna-qt (or
> similar) can I save measured data, yes?
>
> I want to measure the impedance of my antenna at the antenna feed point,
> which of course is outdoors and requires a ladder.  I was hoping to take
> the VNA device only out to the antenna and record the data across the
> amateur bands, bring the unit inside and connect to vna-qt to view and
> analyze the data.  However, it seems I must take the laptop with vna-qt
> with me to the antenna to record the measurements; is that correct?
>
Pretty much, unless you have one of the NanoVNAs that can write to a SD
card.

ANother way, if you've got a helper (or lots and lots of time) is to
measure your feedline. Basically measure it with an open, a load, and a
short (just like a cal). You can use that directly as a cal set, then.

Or (depending on software) you can use that to de-embed the feedline,
and make measurements of the antenna from the comfort of the shack.

yes.. another option is to calibrate the cable out and measure inside the shack.. you just nneed to climb the ladder for connecting open, short and load (at best with a helper in shack who presses open short load buttons for you) ... and if you save that calibration for later use you have that cable included and can measure from shack anytome when you think you have to

but the results over a very long oax are at least questionable ... so a direct read at the antenna would be better (OR USE A SHORT COAX IN THE GARDEN)

greetz sigi dg9bfc

ps you can modify the v2plus4 but that needs some hardware work and a different (modded) firmware

Am 22.08.2022 um 20:36 schrieb Matt Thomas W5MT via groups.io:

>
> I just rcvd my NanoVNA V2Plus4.  I have read through the "official" manual
> and it appears to cover the basics well but I do have one question.  From
> what I gather, there is no data (measurements) storage on the VNA device
> itself, is that correct?  Only using vna-qt (or similar) can I save
> measured data, yes?
>
> I want to measure the impedance of my antenna at the antenna feed point,
> which of course is outdoors and requires a ladder.  I was hoping to take
> the VNA device only out to the antenna and record the data across the
> amateur bands, bring the unit inside and connect to vna-qt to view and
> analyze the data.  However, it seems I must take the laptop with vna-qt
> with me to the antenna to record the measurements; is that correct?
>
> Thank you es 73
> Matt  W5MT

On 8/22/22 8:09 PM, Siegfried Jackstien wrote:
> yes.. another option is to calibrate the cable out and measure inside
> the shack.. you just nneed to climb the ladder for connecting open,
> short and load (at best with a helper in shack who presses open short
> load buttons for you) ... and if you save that calibration for later use
> you have that cable included and can measure from shack anytome when you
> think you have to
>
> but the results over a very long oax are at least questionable ... so a
> direct read at the antenna would be better (OR USE A SHORT COAX IN THE
> GARDEN)
>
> greetz sigi dg9bfc
>

Well, 30 meters (100 ft) of coax might have a few dB of loss at the high
end, which would reduce the SNR of the measurement a bit. But not a lot.

So your S11 magnitude measurement might have a few percent more error in
the dips.